But feather patterns are not directly coded in DNA, and only now has it become clear how birds pull off the feat: it is the result of a tightly choreographed team effort involving stem cells.

The researchers who made the discovery say it could one day help us grow organs from scratch, without the need to put cells on scaffolds that provide the correct shape – although others are sceptical.

Cheng-Ming Chuong from the University of Southern California in Los Angeles and colleagues found a collection of stem cells at the base of feather follicles that give rise to melanocytes: cells that produce the pigment melanin.